5w30 vs 5w40 – Their Similarities And Differences

Engine oils are one of the most important liquids used in engines and as such, you need to be careful when choosing a type for your engine. Their major function is to lubricate different parts of the engine so that they don’t wear out while grinding against each other.

Apart from lubrication, they have a major influence on the efficiency of the fuel consumed. If the engine oil is not good enough, the engine’s power will be significantly reduced.

In making your choice, it’s always best to go with the recommendation of the vehicle’s manufacturer. However, if you’ve misplaced the vehicle’s manual before you had a chance to look at this and you’re out of reach of an automechanic, you might need to take on this project by yourself.

In this case, making an informed decision is in your best interest. This informed decision could only come from thorough research work on the different oil types and the conditions in which they thrive and those at which they diminish in quality.

So, which among these two engine oil types is the best on the market?



When comparing two different oil types, it is best to make these comparisons based on their performance under pressure. For example, regular engine oil tends to get thinner and less effective when heated up and when this happens, it becomes less effective, and the engine is severely affected.

Single grade oils have been known to get pretty thin when they come in contact with hot engine which is why the multi grade ones are better. Therefore, it only makes sense that manufacturers would find a way around this flaw, and that’s where the number rating comes in.

Multi-grade engine oils are manufactured in different ratings that work well in different temperatures and engines. The number that comes after the W is the “hot” viscosity rating of the oil, while the one that comes before it is the “cold” viscosity rating.

The viscosity of an oil is a critical factor that determines the rate of wear of the engine and the efficiency of the fuel used. However, given that heat is the major factor to be worried about, the hot viscosity rating has the most variation among different products, just like in the case of the 5W30 and the 5W40.

See Also : 5w20 vs 5w30 Motor Oil | 5w30 vs 10w30 Synthetic Oil | 5w20 vs 10w30 Vehicle Oil

5w30 Engine Oil

This is the most popular type on the market and that is due to its impressive versatility. The last thing car owners need is to stress about a specific oil type that works for their engine – that’s why the 5W30 is perfect. More importantly, it has a wider range of temperature coverage and doesn’t falter in warm climate periods.

5w40 Engine Oil

5W40 on the other hand is not as common as  5W30 because it doesn’t have as much qualities. The best use for this type is for the promotion of your engine’s health as it has the potential to prevent sludge and buildups in your engine, and as an extension, damages. It tends to circulate more quickly in cold environments even at freezing temperatures. Therefore, it is better suited to colder temperatures than hot ones.



What Is The Difference Between 5W30 and 5W40

The cold adaptation ability of 5W40 is not a very peculiar one as the 5W30 also performs well in cold temperatures. Both of them work quite impressively at normal and cold temperatures and as such lubricate the engine efficiently without the possibility of damage in the engine.

However, as explained earlier, the 5W30 is smoother in the oil pump and is not compromised when the engine is running hot.

This means that the 5W30 is more preferred for long journeys during which you might need to put on the air conditioning system, consume more fuel and expose the vehicle’s engine to more heat. To be on a safer side, it’s best to use the 5W30 but if you don’t get to drive the engine so much that it heats up, or you live in extremely cold regions, using the 5W40 is a good choice.

Moreover, the 5W40 is less expensive and probably more available on the market due to the high market demand of its counterpart. If the viscosity doesn’t mean that much to your engine, then going for the cheaper and more available option is reasonable.

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